L-threonic acid is one of metabolites of vitamin C. It is reported that some physiological functions of vitamin C were exerted very possibly by some of its metabolites, for example, L-threonic acid and the like. In the other hand, the existing of these compounds could profoundly influence the uptake and utilization of vitamin C.
Calcium L-threonate is a derivative of L-threonic acid. Calcium L-threonate can improve uptake of vitamin C by the lymphoma cells and can be used as the high efficient calcium nutrient for preventing and treating varied diseases caused by calcium deficiency (Chinese Patent, ZL 96 06507.9). Also, calcium L-threonate is useful for allaying inflammation and reducing blood pressure. But there was no report for other salts of L-threonic acid and their use as drugs on treating diseases.
Anemia is a common disease, which is caused by a various reasons. Their reasons mainly include: (1) a decrease of red blood corpuscle (RBC) in volume or in quantity; (2) a decrease of hemoprotein in amount due to chronic or acute blood loss and the injury of RBC due to its exposing to some chemical compounds; and (3) a reduction of the number of produced RBC due to deficiency of marrow or such nutrients as ferrous and vitamin B.sub.12 used to produce RBC.
Nutritional iron-deficiency anemia (IDA) is a very common case among anemia diseases. The reason is that the body iron balance between excretion and storage has not been sustained. Consequently, there was more and more excretion but less and less storage of body iron with time. These phenomena often happened during the periods of growth, pregnancy and chronic blood loss due to various reasons. For example the less intake of iron from food is an important factor to lead to iron deficiency for body.
In fact, the nutritional IDA is a worldwide nutritional problem. For treating this kind of disease, simply taking iron-rich foods is hard to have good effects compared with using drugs. Among IDA drugs of iron preparations, ferrous sulfate is a relative popular drug with good effectiveness, low price and abundant resource. Even so, the extensive application of ferrous sulfate for treating IDA is limited because of its side effects (Chinese Child Blood, Vol. 1, p24-26, 1996). Therefore, it is desirable to provide new active compounds and compositions thereof for improving and treating IDA very efficiently.
Blood-loss anemia is a usual case of anemia. Most patients are women in the periods of pregnancy and menses.
Another anemia is hemolytic anemia. It is mainly caused by the following reasons: exposing to hemolytic chemical materials such as naphthalene and sulfanilamide; production of antibody in cells due to administration of drugs; and presence of cells with hereditary defection in body. A method for treating hemolytic anemia is to remove those harmful chemical reagents from body. Therefore, it is desirable to provide an active compounds and compositions thereof so as to improve and treat hemolytic anemia. It is in particularly desirable to provide an active compound and composition thereof so as to improve and cure these three kinds of anemia diseases.